1. Field of the Invention
The present invention relates generally to robotic retrieval/delivery devices and methods of using the same, and, more particularly, the present invention is directed to asset ordering, tracking and delivery methods utilizing an autonomous robotic tug and cart.
2. Description of the Background
Robotic and automated vehicles for delivering or transporting materials indoors have been developed and utilized in a number of very specialized applications. For example, several attempts have been made to design and use a mail delivery robot that makes regular stops to make deliveries on a somewhat regular basis. Likewise, one or more attempts at using an unmanned robot to push or pull a cart around a predefined circuit have also been contemplated. However, rather than being an independent (i.e., autonomous) vehicle, these robots are typically automated guided vehicles that follow a predefined track such as an ultraviolet track painted on the ground, a hidden guide wire or some other means of providing a predefined path for the vehicle.
In many different pursuits, delivery tasks are repeated on a daily if not hourly basis. Even in the relatively defined space of enclosed buildings, there are an almost limitless number of applications where people are used to perform repeated delivery tasks that require little or no critical thinking on a day-to-day basis. For example, in a hospital setting, hospital employees spend an exceedingly large amount of time pushing carts around the hospital and delivering small goods to various locations throughout the hospital. No matter which employee undertakes these errands, high cost human resources are being wasted on tasks that could be automated. Heretofore, however, no cost-effective solution to this delivery problem has been available.
Certain previous robots have been designed to address the problem of navigation and tracking the position of a robot as it travels in an indoor environment. For example, U.S. Pat. No. 7,100,725, which is assigned to the owners of the present invention and is incorporated herein by reference in its entirety, describes certain features of a robotic cart pulling vehicle that address the navigation and location problem. However, there are many other aspects of utilizing such a robotic device that are not addressed therein.
Another example of prior art systems include a class of mobile robotic devices that navigate based on predefined linear movement commands. For example, to move from one location to another, the device may attempt to execute commands to: (a) move 10 feet forward; (b) turn left; and (c) move 8 feet forward. While these navigation methodologies are useful, they introduce a high degree of positional error. As additional movement commands are carried out, additional error enters the process. As such, an autonomous delivery system in which sensors are used to constantly confirm/update positional accuracy is sought in this art.
In addition to simply navigating the terrain, a preferred robotic retrieval/delivery system would include a variety of different features and characteristics, none of which have been included in combination in previous robotic tug/cart systems. For example, the robotic tug should include a variety of different redundant sensors that allow it to detect potential obstacles before impact and to confirm positional accuracy to a high degree. The tug should also include certain visual and audible cues as to its current and next intended actions in order to more seamlessly coexist in an environment dominated by humans.
In varied environments, the robotic tug system should provide solutions to work around and through certain commonly encountered obstacles. For example, the robotic tug and cart should be able to move from one floor to another in a multi-story building. The device should be able to manipulate automatic doors or otherwise complete delivery tasks when faced with closed doors. These and other “non-ideal” aspects of real world environments have not heretofore been appropriately addressed by existing robotic applications.
A robotic tug delivery system should also provide a variety of different communication and interface options for all levels of users of the system. For example, as the robotic tug moves, it is desirable to have the tug remain in communication with computers at its present location. Moreover, it would be beneficial to allow for broadband communication to a remote host, for example an entity that oversees the implementation and monitoring of robotic tugs at a variety of different physical locations at the same time.
The present invention, in its preferred embodiments, addresses the above-mentioned limitations of the prior art by providing a cost-effective alternative to employees pushing carts to make deliveries of various goods. Moreover, although many aspects of the present invention will be described with reference to a preferred embodiment in a hospital setting (a particularly good application of the present invention), the invention may be applied to a wide variety of delivery-related tasks in many alternative environments within the scope of the present invention.